The present inventive subject matter relates to the imaging arts. It finds particular application in conjunction with phase change or solid ink jet image rendering devices, and will be described with particular reference thereto. However, one of ordinary skill in the art will appreciate that it is also amenable to other like applications.
In general, a phase change or solid ink jet printer (or other like image producing or rendering machines, e.g., copiers, fax machines, multi-function devices, etc.) employs inks that are in a solid phase at ambient temperature, but exist in a molten or melted liquid phase at an elevated operating temperature of the printer. At the elevated operating temperature, droplets or jets of the molten or liquid phase ink are ejected from a printhead of the printer onto a printing media. Such ejection can be directly onto a final image receiving substrate, or indirectly onto an imaging member before transfer from it to the final image receiving media. In any case, when the ink droplets contact the surface of the printing media, they solidify to create an image in the form of a predetermined pattern of solidified ink drops.
An example of a phase change ink image producing machine or printer is disclosed in U.S. Pat. No. 5,372,852 issued Dec. 13, 1994 to Titterington, et al., incorporated by reference herein in its entirety. As disclosed therein, the phase change ink printing process includes raising the temperature of a solid form of the phase change ink so as to melt it and form a molten liquid phase ink. It also includes applying droplets of the phase change ink in a liquid form onto an imaging surface in a pattern using a device such as an ink jet printhead. The process then includes solidifying the phase change ink droplets on the imaging surface, transferring them to the image receiving substrate, and fixing the phase change ink to the substrate.
Conventionally, the solid form of the phase change ink is a “stick”, “block”, “bar” or “pellet” as disclosed for example in U.S. Pat. No. 4,636,803 (rectangular block, cylindrical block); U.S. Pat. No. 4,739,339 (cylindrical block); U.S. Pat. No. 5,038,157 (hexagonal bar); U.S. Pat. No. 6,053,608 (tapered block with a stepped configuration), all incorporated herein by reference in their entirety. Further examples of such solid forms are also disclosed in design patents such as U.S. Pat. No. D453,787 issued Feb. 19, 2002, also incorporated herein by reference in its entirety. In use, each such block form “stick”, “block”, “bar” or “pellet” is fed into a heated melting device that melts or phase changes the “stick”, “block”, “bar” or “pellet” into a print head reservoir for printing as described above.
The printhead that ejects or jets the phase change ink is, on occasion, cleaned, e.g., to maintain performance of the printer and preserve image quality. Commonly, during a cleaning cycle, a scraper or wiper blade is drawn across the ink ejecting face of the printhead to squeegee away any excess liquid phase ink that may collect there. The waste ink wiped-off or otherwise removed from the face of the printhead is typically allow to drop (typically, still in liquid from) directly from the printhead into a collection pan or waste container where it cools and re-solidifies. When the collection pan is full, it is removed, manually emptied and then returned.
While generally acceptable, the foregoing approach to waste ink disposal has certain drawbacks and/or limitations. For example, manual emptying of the collection pan may be deemed undesirable in certain circumstances. Being that the collection pan receives the waste ink directly from the printhead, it is often located inside the printer positioned under the printhead. This location potentially complicates the access to and/or removal of the collection pan. In such instance, e.g., because the printer may have to be opened up to access the collection pan, it may not be able to operate at all while the pan is being emptied.
The collection and disposal of waste phase change ink presents certain challenges in general. For example, one challenge is to guard against the waste ink splattering out of the collection pan when it is drop therein from a distance, e.g., in its liquid form. Another challenge is to collect the waste ink so that its level is maintained substantially even as it is being collected. FIG. 1, for example, shows a prior art approach in which the waste ink tends to form stalagmites 200 in a collection pan 202. This phenomena is experienced when ink 204 still in its molten form, but near its freezing point, drips from the printhead 206 onto solid ink 208 already collected, e.g., already at or near ambient temperature. As a result, the ink that is deposited into the waste container or collection pan 202 tends to freeze or re-solidify rather quickly, i.e., before it has had a chance to spread out evenly. Stalagmite growth of this kind is generally undesirable because a build-up may route waste ink into one side of the collection pan or the other, thus resulting in a container that is only partially full, or eventually the top of the stalagmite may reach the inlet to the collection pan and may block it off.
Accordingly, a new and improved apparatus and/or method for disposal of waste ink in a solid ink jet printer is disclosed that overcomes the above-referenced problems and others.